JP2534079Y2 - Artificial diamond deposition equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial diamond deposition apparatus capable of depositing artificial diamond having good crystallinity.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed and put to practical use as a method for depositing and producing artificial diamond. In particular, a material to be treated such as a substrate is decomposed by decomposing a reaction gas by a heated filament (high energy substance). The method of precipitating artificial diamond on the surface is particularly attracting attention because a stable artificial diamond film can be formed at a high speed with a relatively simple apparatus.

In the above-mentioned method, for example, an artificial diamond deposition apparatus (hereinafter simply referred to as a deposition apparatus) 1 as shown in FIG. 5 is used. The deposition apparatus 1 includes a reaction chamber 3 made of quartz for depositing diamond on a substrate (material to be processed) 2, a hydrocarbon such as CH ₄ , C ₂ H _2, etc. A reaction gas introduction pipe 4 made of Mo for introducing a reaction gas G composed of H ₂ gas serving as a carrier gas, and a reaction gas discharge pipe 5 for discharging the reaction gas G from the reaction chamber 3. I have.

The reaction chamber 3 is provided with an elevating device 8 which is controlled by a control mechanism 6 and is movable vertically in the reaction chamber 3 and can be fixed at an arbitrary position. A work holder 9 made of Mo for supporting a plurality of substrates 2 is fixed to 8a. A thermocouple 10 is attached to the lower surface of the work holder 9.

The reaction chamber 3 has a surface 2 of a substrate 2 supported by a work holder 9 moved to a position above the reaction chamber 3.
A spiral filament (high-energy body) 11 made of metal tungsten (W) or metal tantalum (Ta) is horizontally provided at a position above a predetermined interval opposed to a. An electric furnace 12 for heating the reaction chamber 3 is provided around the reaction chamber 3.

Next, a method of forming a diamond film on the surface 2a of the substrate 2 using the deposition apparatus 1 will be described. First, the reaction gas G is introduced into the reaction chamber 3 using the reaction gas introduction pipe 4, and the reaction gas G is caused to flow vertically downward from the filament 11 toward the work holder 9, and the reaction gas G is discharged through the reaction gas discharge pipe 5. Discharge to the outside of the room 3.

During this time, the atmospheric pressure in the reaction chamber 3 is increased from 10 to
Hold the filament 11 at 15
The temperature of the surface 2a of the substrate 2 disposed below the predetermined interval is raised to 800 to 1000 ° C. by using the electric furnace 12 while heating to 00 to 2500 ° C. to activate the reaction gas G by heating.
The reaction gas G is thermally decomposed in this state to deposit artificial diamond on the surface 2a of the substrate 2.

In this case, the reaction gas G is supplied to the filament 11
To become activated free carbon (C),
The activated free carbon flows from above the substrate 2 toward the periphery 13 of the work holder 9, and the activated free carbon is quickly deposited on the surface 2 a of the substrate 2, and a graphite structure and a diamond structure are mixedly formed on the surface 2 a. Is done. Here, since the graphite structure is a weaker structure, it is selectively removed from the surface 2a by atomic hydrogen (H) generated when the reaction gas G is decomposed, leaving only the diamond structure. The substrate 2 on which the diamond is deposited is moved downward by a predetermined distance by the elevating device 8, and is naturally cooled.

[0009]

However, the above-mentioned deposition apparatus 1 has the following disadvantages. That is, FIG.
As shown in (1), the flow of the reaction gas G from the filament 11 to the work holder 9 cannot pass through the work holder 9 and therefore flows toward the periphery 13 of the work holder 9 and flows downward from the periphery 13. The activated free carbon is applied to the substrate 2 outside the central substrate 2.
Will accumulate more.

On the surface 2a of the substrate 2 disposed outside, the free carbon is quickly deposited and the graphite structure of the weak bond is selected from the surface 2a by the atomic hydrogen (H) generated when the reaction gas G is decomposed. Although a good artificial diamond can be deposited and deposited, a good flow of the reactive gas G occurs on the surface 2a of the substrate 2 disposed at the center, and is deposited on the surface 2a of the substrate 2 because the flow of the reaction gas G is weak. Various problems arise, such as the amount of free carbon is small and the graphite structure cannot be selectively removed. Therefore,
Good artificial diamond is deposited only on the substrate 2 disposed on the outside, and has a disadvantage that the product yield is extremely poor.

Since a considerable reaction time is required to deposit the artificial diamond, the above-described reduction in the product yield significantly reduces the efficiency of the apparatus. The present invention has been made in view of the above circumstances, and has as its object to provide a deposition apparatus capable of effectively solving the above-mentioned disadvantages.

[0012]

In order to solve the above problems, the present invention employs the following deposition apparatus. That is, a reaction chamber for depositing diamond on the material to be processed, a reaction gas introduction pipe for introducing a reaction gas into the reaction chamber,
A reaction gas discharge pipe for discharging a reaction gas from the reaction chamber;
A workpiece holder for supporting said workpiece, said Wakuho
At a position facing the surface of the workpiece to be processed
In synthetic diamond deposition apparatus comprising; and a filament provided, the workpiece holder and the filament
A box body surrounding them, a suction port for introducing the reaction gas at one end , and an exhaust port for discharging the reaction gas at the other end , and a plurality of work holders. Are formed.

[0013]

In the deposition apparatus of the present invention, the work holder is
By providing a box having an intake port for introducing the reaction gas at one end and an exhaust port for discharging the reaction gas at the other end , so as to surround these around the filament ,
The reaction gas inside the box is caused to stay, and the reaction gas is thermally decomposed uniformly over a wide range.

Further, since a plurality of holes are formed in the work holder, the flow of the reaction gas from the filament to the work holder becomes a uniform laminar flow, and the activated gas generated by being decomposed by the filament is produced. The free carbon is uniformly deposited on the surface of the workpiece held by the work holder.

Further, since the reaction gas flows into the inside of the box from the air inlet, the pressure inside the box is higher than the outside, and the differential pressure becomes positive. Therefore, the reaction gas staying inside the box becomes a uniform laminar flow toward the work holder due to the differential pressure, and flows down uniformly from the work holder and a narrow portion between the box and the work holder.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The depositing device 21 of the present invention is obtained by providing a box 22 around the work holder 9 and the filament 11, which are the components of the depositing device 1 described in the conventional example, so as to surround them, and further improving the work holder 9. The same components as those of the box 22 and the improved work holder are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, the box body 22 is formed of a quartz box having a substantially rectangular parallelepiped outer shape.
A suction port 24 for introducing the reaction gas G is formed at the center of the nozzle, and a nozzle 25 projecting vertically upward is attached to the suction port 24. The lower portion of the box 22 is opened to serve as an exhaust port 26 for discharging the reaction gas G.

As shown in FIG. 2, the work holder 31 has a net made of Mo (a plurality of holes) 33 formed in a portion excluding the periphery of a circular quartz plate 32. As shown in FIG.

Next, the box 22 and the work holder 31
1 will be described with reference to FIG. The reaction gas G introduced into the reaction chamber 3 becomes a uniform laminar flow while passing through the nozzle 25, and flows into the inside 27 of the box 22 from the suction port 24. The inflowing reaction gas G is applied to the side wall 2 of the box 22.
It is confined in the inside 27 by the work holder 8 and the work holder 31 and stays in the inside 27. During this time, the reaction gas G is uniformly pyrolyzed by the filament 11 to become activated free carbon (C).

Further, since the net 33 is formed in the work holder 31, the flow of the reaction gas G from the filament 11 toward the work holder 31 becomes a uniform laminar flow in the vertical direction, and is generated by being decomposed by the filament 11. The activated free carbon is uniformly deposited on the surfaces of the substrates 2 held by the work holder 32. A graphite structure and a diamond structure are mixedly formed on the surface 2a. The graphite structure is selectively and satisfactorily removed from the surface 2a by atomic hydrogen (H) generated when the reaction gas G is decomposed. Only the diamond structure remains. Therefore, the graphite structure with a weak bond is selectively removed, and an artificial diamond having extremely high crystallinity is deposited.

Since the reaction gas G flows into the inside 27 of the box 22 from the intake port 24, the inside 27 of the box 22 has a higher pressure than the outside 29 and the differential pressure becomes positive. . Therefore, the reaction gas G staying in the inside 27 of the box 22 becomes a uniform laminar flow toward the work holder 31 due to the differential pressure, and the net 33 of the work holder 31 and the space between the box 22 and the work holder 31 are formed. It flows down uniformly from the constriction 35.

Now, the work holder 31 and the filament 11 are surrounded by a box 22, and the reaction gas composition: H ₂ / CH ₄ = 1000 cc / min / 10 cc / min in a volume ratio between the filament 11 and the surface 2 a of the substrate 2. Distance: 50 mm Atmospheric pressure in the reaction chamber 3: 50 torr Heating temperature of the filament 11: 2000 ° C. Reaction time: 5 hours Cooling: Natural cooling (furnace cooling) was performed to deposit artificial diamond. An artificial diamond film having an average film thickness of 4 μm was uniformly formed. In addition, a uniform artificial diamond film was formed on all of the substrates 2 held by the work holder 21, and it was found that the product yield was significantly improved as compared with the related art.

As described above, according to the deposition apparatus of the present invention, the intake port 24 is formed in the top plate 23 at the upper part of the box 22, and the lower part is opened to form the exhaust port 26. The reaction gas G can be effectively confined in the inside 27 of the box 22, can be retained for a long time, and the reaction gas G can be thermally decomposed uniformly.

Since the work holder 31 is formed with the Mo net 33 except for the periphery of the circular quartz plate 32, the flow of the reactive gas G containing free carbon flows toward the work holder 31. A uniform laminar flow is obtained, and the free carbon can be uniformly and rapidly deposited on the surface 2a of the substrate 2 held by the work holder 31, and the weakly bonded graphite structure is selectively removed by the atomic hydrogen, and is extremely reduced. An artificial diamond having good crystallinity can be deposited.

Further, the inside 27 of the box body 22 is
Since the pressure is higher and the differential pressure becomes positive, the reaction gas G staying in the interior 27 of the box 22 becomes a uniform laminar flow toward the work holder 31 due to the differential pressure, and
The first net 33 and the narrow portion 35 between the box body 22 and the work holder 31 can uniformly flow downward.

As described above, the artificial diamond can be uniformly formed on the surfaces 2a of all the substrates 2 held by the work holder 31, and the product yield can be greatly improved.

The work holder 41 of FIG. 3 is also an improvement of the work holder 9 of the prior art, like the work holder 31. The work holder 41 has a circular quartz plate 4.
A grid (a plurality of holes) 43 is formed by punching in a portion except for the periphery of 2. This work holder 4
1 has exactly the same operation and effect as the work holder 31.

The work holder 51 shown in FIG. 4 is an improvement of the conventional work holder 9 like the work holders 31 and 41. The work holder 51 has a plurality of holes 53,... Formed by punching in a portion excluding the periphery of a circular quartz plate 52. This work holder 5
1 has exactly the same functions and effects as those of the work holders 31 and 41.

[0029]

As described above, according to the deposition apparatus of the present invention, a reaction chamber for depositing diamond on a material to be processed, a reaction gas introduction pipe for introducing a reaction gas into the reaction chamber, and a reactant gas discharge pipe for discharging the reaction gas from the reaction chamber, a workpiece holder for supporting said workpiece, said ring
Facing the surface of the material to be processed supported by the workpiece holder
In synthetic diamond deposition apparatus comprising; and a filament provided at a position, the workpiece holder and Fi
Provide a box surrounding these around the lament , and in the box,
At one end , an intake port for introducing the reaction gas is provided.
An exhaust port provided for discharging the reaction gas to the other end, the Wakuho
Since it was decided that multiple holes were formed in Luda ,
The reaction gas introduced into the reaction chamber is effectively confined inside the box, can be retained for a long time, and the reaction gas can be thermally decomposed uniformly.

Further, since a plurality of holes are formed in the work holder, the flow of the reactive gas containing free carbon becomes a uniform laminar flow toward the work holder.
The free carbon can be uniformly and quickly deposited on the surface of the material to be processed held by the work holder, and the graphite structure of the weak bond is selectively removed by atomic hydrogen to produce an artificial diamond having extremely high crystallinity. Can be deposited.

Since the pressure inside the box is higher than the outside and the differential pressure becomes positive, the reactant gas staying inside the box is uniformly laminar flowing toward the work holder due to the differential pressure. Thus, the fluid can be uniformly discharged from the plurality of holes of the work holder and the narrow portion between the box body and the work holder.

As described above, the artificial diamond can be uniformly formed on the surfaces of all the workpieces held by the work holder, and the product yield can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a box and a work holder of a deposition apparatus of the present invention.

FIG. 2 is an overall perspective view showing an example of a work holder of the deposition apparatus of the present invention.

FIG. 3 is an overall perspective view showing an example of a work holder of the deposition apparatus of the present invention.

FIG. 4 is an overall perspective view showing an example of a work holder of the deposition apparatus of the present invention.

FIG. 5 is a schematic view of a conventional deposition apparatus.

FIG. 6 is a diagram showing a flow of a reaction gas in a conventional deposition apparatus.

[Explanation of symbols]

 Reference Signs List 21 artificial diamond deposition apparatus 2 substrate (material to be treated) 2a surface 3 reaction chamber 4 reaction gas introduction pipe 5 reaction gas discharge pipe 6 control mechanism 8 lifting apparatus 9 work holder 10 thermocouple 11 filament (high energy body) 12 electric furnace 22 Box 23 Top plate 24 Intake port 25 Nozzle 26 Exhaust port 27 Inside 28 Side wall 29 Outside 31 Work holder 32 Quartz plate 33 Mesh (multiple holes) 35 Narrow portion 41 Work holder 42 Quartz plate 43 Lattice (Multiple holes) 51 Work Holder 52 Quartz plate 53 Hole

Claims (1)

(57) [Scope of request for utility model registration] A reaction chamber for depositing diamond on a material to be processed, a reaction gas introduction pipe for introducing a reaction gas into the reaction chamber, a reaction gas discharge pipe for discharging a reaction gas from the reaction chamber, a workpiece holder for supporting an object to be treated, prior to
Facing the surface of the material to be processed supported by the work holder
An artificial diamond deposition apparatus comprising a filament provided at a position where the work holder and the filament are provided around the work holder and the filament ; and an inlet for introducing the reaction gas at one end of the box. And an exhaust port for discharging a reaction gas is provided at the other end , and a plurality of holes are formed in the work holder.